Efficacy of dioic acid compared with hydroquinone in the treatment of melasma.

BACKGROUND: Melasma is a common disorder of pigmentation characterized by relatively symmetric, brown or gray-brown patches on sun-exposed facial areas. Hydroquinone, the most effective agent in melasma, is known to irritate the skin, and so new alternatives in the treatment of melasma are required. We sought to assess the clinical response of a new depigmenting agent in melasma. METHODS: Ninety-six Mexican female patients with melasma were enrolled in this open, comparative, 12-week study. The patients received 1% dioic acid cream (twice daily) or 2% hydroquinone cream (twice daily). RESULTS: There was a significant difference in the Melasma Area Severity Index (MASI) scores from baseline to the end of the study using treatment with dioic acid (baseline, 14.52 3.4; after 12 weeks of treatment, 6.05 +/- 1.2; P = 0.001) and hydroquinone (baseline, 15.22 +/- 2.4; after 12 weeks of treatment, 6.34 +/- 1.3; P = 0.001); however, there were no significant differences between treatments (baseline, P = 0.311; after 12 weeks of treatment, P = 0.287). The side-effects were similar with both medications; however, pruritus was more common in patients using hydroquinone. CONCLUSIONS: Dioic acid is an effective and highly tolerated skin product, although further controlled, blind, multicenter studies are required to support these results.

Acetoacetate protects hippocampal neurons against glutamate-mediated neuronal damage during glycolysis inhibition.

Glucose is the main substrate that fulfills energy brain demands. However, in some circumstances, such as diabetes, starvation, during the suckling period and the ketogenic diet, brain uses the ketone bodies, acetoacetate and beta-hydroxybutyrate, as energy sources. Ketone body utilization in brain depends directly on its blood concentration, which is normally very low, but increases substantially during the conditions mentioned above. Glutamate neurotoxicity has been implicated in neurodegeneration associated with brain ischemia, hypoglycemia and cerebral trauma, conditions related to energy failure, and to elevation of glutamate extracellular levels in brain. In recent years substantial evidence favoring a close relation between glutamate neurotoxic potentiality and cellular energy levels, has been compiled. We have previously demonstrated that accumulation of extracellular glutamate after inhibition of its transporters, induces neuronal death in vivo during energy impairment induced by glycolysis inhibition. In the present study we have assessed the protective potentiality of the ketone body, acetoacetate, against glutamate-mediated neuronal damage in the hippocampus of rats chronically treated with the glycolysis inhibitor, iodoacetate, and in hippocampal cultured neurons exposed to a toxic concentration of iodoacetate. Results show that acetoacetate efficiently protects against glutamate neurotoxicity both in vivo and in vitro probably by a mechanism involving its role as an energy substrate.

The treatment of melasma. 20% azelaic acid versus 4% hydroquinone cream.

The efficacy of 20% azelaic acid cream and 4% hydroquinone cream, both used in conjunction with a broad-spectrum sunscreen, against melasma was investigated in a 24-week, double-blind study with 329 women. Over the treatment period the azelaic acid cream yielded 65% good or excellent results; no significant treatment differences were observed with regard to overall rating, reduction in lesion size, and pigmentary intensity. Severe side effects such as allergic sensitization or exogenous ochronosis were not observed with azelaic acid.

[Double-blind clinical study of the treatment of melasma with azelaic acid versus hydroquinone]. / Estudio clínico doble ciego en el tratamiento del melasma entre ácido azelaico versus hidroquinona.

A comparative double-blind study was carried out on sixty patients received oral contraceptives. Patients were treated with 20% azelaic acid or 4% hydroquinone. They were observed for 24 weeks and the results compared and checked for side effects. The results showed that the azelaic acid was not better than the hydroquinone in the treatment of melasma but it could be used as alternative drug.